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Tetracosane

Tetracosane structure

Tetracosane 

structure

Description

WHITE SHINY FLAKES


N-tetracosane is a crystalline waxy solid. Insoluble in water. Used in organic synthesis.|Solid


N-tetracosane is a crystalline waxy solid. Insoluble in water. Used in organic synthesis.|Tetracosane is a straight-chain alkane containing 24 carbon atoms. It has a role as a plant metabolite and a volatile oil component.

Tetracosane Basic Attributes

338.65

338.65

211-474-5

YQ5H1M1D7I

2984

DTXSID8060955

Crystals|Crystals from ether|White powder

2901100000

Characteristics

0

12.13 (est)

White Shiny Flakes

0.7991 g/cu cm at 20 deg C

54 °C

391.3 °C

>230 °F

1.446

Insoluble in water.chloroform: soluble 10%, clear, colorless

Store below +30°C.

4.07X10-6 mm Hg at 25 deg C (extrapolated)

Henry's Law constant = 280 atm-cu m/mol at 25 °C (est)

Refractive index = 1.4283 at 70 °C/D|Hydroxyl radical reaction rate constant = 3.09X10-11 cu cm/molecule-sec at 25 °C (est)

Insoluble in water.

Hydrocarbons, Aliphatic Saturated

Saturated aliphatic hydrocarbons, such as N-TETRACOSANE, may be incompatible with strong oxidizing agents like nitric acid. Charring of the hydrocarbon may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. When heated sufficiently or when ignited in the presence of air, oxygen or strong oxidizing agents, they burn exothermically to produce carbon dioxide and water.

Safety Information

NONH for all modes of transport

3

24/25

Stable under recommended storage conditions.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.|Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contaminated packaging: Dispose of as unused product.

Incompatible materials: Strong oxidizing agents.

Flash point data for this compound is not available,but it is probably combustible. (NTP, 1992)

SMALL SPILLS AND LEAKAGE: If you spill this chemical, dampen the solid spill material with 5% ammonium hydroxide, then transfer the dampened material to a suitable container. Use absorbent paper dampened with 5% ammonium hydroxide to pick up any remaining material. Your contaminated clothing and the absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with 5% ammonium hydroxide followed by washing with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned. STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. RECOMMENDED GLOVE MATERIALS: Permeation data indicate that butyl rubber gloves may provide protection to contact with this compound. Butyl rubber over latex gloves is recommended. However, if this chemical makes direct contact with your gloves, or if a tear, hole or puncture develops, remove them at once. (NTP, 1992)|Eye/face protection: Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place.|Respiratory protection is not required. Where protection from nuisance levels of dusts are desired, use type N95 (US) or type P1 (EN 143) dust masks. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.

ACCIDENTAL RELEASE MEASURES Personal precautions, protective equipment and emergency procedures: Avoid dust formation. Avoid breathing vapors, mist or gas. Environmental precautions: Do not let product enter drains. Methods and materials for containment and cleaning up: Sweep up and shovel. Keep in suitable, closed containers for disposal.

ACCIDENTAL RELEASE MEASURES Personal precautions, protective equipment and emergency procedures: Avoid dust formation. Avoid breathing vapors, mist or gas. Environmental precautions: Do not let product enter drains.|Precautions for safe handling: Provide appropriate exhaust ventilation at places where dust is formed. Normal measures for preventive fire protection.|Appropriate engineering controls: General industrial hygiene practice.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|For more Preventive Measures (Complete) data for n-Tetracosane (6 total), please visit the HSDB record page.

/Higher alkanes/ may cause eye and skin irritation.

Tetracosane was identified in the extract of some plastic materials from Concon, Chile(1); it was detected in the surface extract of new plastic bags, roadside litter, and landfill trash at concentrations of 93.5, 117.1, and 154.5 ug/g, respectively; it was detected in the particulate matter of open burn smoke from new plastic bags, roadside litter, and landfill trash, at concentrat646ions of 21.5, 20.8, and 12.6 ng/mg, respectively; eicosane was detected in the surface extract and the open burn smoke of new plastic bags from the United States at a concentration of 56.3 ug/g and 55.2 ng/mg, respectively(1). Average concentrations of tetracosane emitted as a result of Chinese cooking styles were reported as 135, 102, 54, and 66 ng/mg, for Cantonese style, Sichuan style, Dongbei style, and Hunan style cooking, respectively(2).

SEDIMENTS: Tetracosane was detected in sediment samples from from 14 sites along the Shinano River in Japan, from Nov 2005 to April 2006, at concentrations ranging from 3.0 to 38 ng/g(1).|SOIL: During winter 2002 soil and sand samples, from six locations in the Riyadh metropolitan area of Saudi Arabia, were examined for extractable organic matter; tetracosane was detected at relative concentrations between 0.24 to 0.81% (of total extractable organic matter) at five of six locations(1).

URBAN/SUBURBAN: In 2002, tetracosane was detected in the gas-phase and the particulate-phase of urban and industrial air samples from Prato, Italy, at average concentrations of approximately 12 and 8.5 ng/cu m, respectively(1). Tetracosane was detected in the particulate matter of ambient urban air sampled daily from January 2003 through December 2004 in Augsburg, Germany; average concentrations reported for spring, summer, fall and winter were 6.33, 3.19, 8.74, and 13.8 ng/cu m, respectively(2). During late fall and winter seasons tetracosane was monitored in the particulate matter of ambient atmospheres in urban areas of Corvallis OR, Guangzhou China, Beijing China, and Taiyuan China, with reported concentrations of 1.0, 57.3, 148.4, and 63.4 ng/cu m, respectively(3).|SOURCE DOMINATED: Tetracosane was detected in the particle phase of tailpipe emissions from catalyst equipped gasoline powered motor vehicles at a concentration of 0.9 ug/km; and in the gas and particle phase of tailpipe emissions from non-catalyst equipped gasoline powered motor vehicles at concentrations of 8.9 and 503 ug/km, respectively; it was also detected in the gasoline at 1.7 ug/g(1). Concentrations of various compounds including alkanes were reported near a highway in Raleigh, NC with an annual average daily traffic count of approximately 125,000 vehicles. High volume PM2.5 air samples were collected at two locations, one approximately 10 meters (near) and the other 275 meters perpendicular (far) from the road(2). Mean (range) tetracosane concentrations were 340 (74-870) and 220 (100-550) pg/cu m at the near and far sites, respectively(2). Tetracosane was detected in the particulate phase of emissions from light-duty vehicles using diesel fuel at concentrations ranging from 9.69 to 27.62 ug/mg for vehicle with an emission control device and 201.2 ug/mg for the vehicle without an emission control device(3). Field sampling, conducted during June-July 2005 and January 2006, of particulate matter collected roadside of an interstate highway in Atlanta GA, 400 meters away from the freeway at the Georgia Tech campus, and at a rural site in Yorkville GA, had tetracosane concentrations of approximately 7.8, 5.3, and 3.2 ng/cu m, respectively(4).

Toxicity

IDENTIFICATION AND USE: Tetracosane is a solid n-alkane containing 24 carbon atoms (C24). Solid n-alkanes (paraffin waxes) are used in a variety of applications: as feeds for cracking them to gasoline blendstock materials, oxidation, and chlorination reactions. HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: A homologous series of n-alkanes ranging from n-C12-n-C31 was found in all samples of bovine tissues.

Tetracosane is detected in various plants used in food and medicinal applications(1). Tetracosane is found in the mineral evenkite found in the French Alps(2).

Alkanes such as tetracosane may be components in petroleum products(1) and may be released to the environment through the processing and combustion of petroleum products(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 6.5X10+6(SRC), determined from a structure estimation method(2), indicates that tetracosane is expected to be immobile in soil(SRC). Volatilization of tetracosane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 280 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption to soil is expected to attenuate volatilization(SRC). Tetracosane is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.07X10-6 mm Hg at 25 °C(4). Biodegradation oxygen consumption of 8.2 ug/mL using a soil suspension(4) indicates that biodegradation of tetracosane may be a slow environmental fate process in soil(SRC).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 6.5X10+6(SRC), determined from a structure estimation method(2), indicates that tetracosane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 280 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 1.9 hours and 7.3 days, respectively(SRC). However, adsorption to sediment and suspended solids is expected to attenuate volatilization(SRC). The estimated volatilization half-life from a model pond is greater than 2 years if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 40(SRC), from an estimated log Kow of 11.64(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Biodegradation oxygen consumption of 8.2 ug/mL using a soil suspension(4) indicates that biodegradation of tetracosane may be a slow environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetracosane, which has a vapor pressure of 4.07X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tetracosane is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 12 hours(SRC), calculated from its rate constant of 30.9X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase tetracosane may be removed from the air by wet and dry deposition(SRC). Tetracosane does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of tetracosane with photochemically-produced hydroxyl radicals has been estimated as 30.9X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 12 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tetracosane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Tetracosane does not contain chromophores that absorb at wavelengths >290 nm(3) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 40 was calculated in fish for tetracosane(SRC), using an estimated log Kow of 12.13(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

The Koc of tetracosane is estimated as 6.5X10+6(SRC), using an estimated log Kow of 12.13(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that tetracosane is expected to be immobile in soil.

The Henry's Law constant for tetracosane is estimated as 280 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that tetracosane is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 1.9 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 7.3 days(SRC). However, adsorption to soil is expected to attenuate volatilization(SRC). The estimated volatilization half-life from a model pond is greater than 2 years if adsorption is considered(4). Tetracosane is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.07X10-6 mm Hg(5).

DRINKING WATER: Tetracosane was identified but not quantified in tap water samples from 2 sites in Tsukuba, Japan, June 1983(1).|SURFACE WATER: Tetracosane concentrations ranged from 0.12 to 0.63 ug/L in eight stations located in the Guanabara Bay Basin, Rio de Janeiro, Brazil, sampled from September 2011 to August 2012(1).|RAIN/SNOW/FOG: Tetracosane was detected in 9 out of 10 snow samples collected in March 1999 from rural and urban areas in Russia and Finland at concentration ranging from 0.05 to 17.9 ug/kg(1).

According to the 2012 TSCA Inventory Update Reporting data, there are 0 reporting facilities for tetracosane(1).|Occupational exposure to tetracosane may occur through inhalation and dermal contact with this compound at workplaces where tetracosane is produced or used. Monitoring data indicate that the general population may be exposed to tetracosane via inhalation of ambient air, ingestion of food and dermal contact with water contaminated by combustion effluents(SRC). The greatest potential for dermal and inhalation exposure is expected during use of petroleum products containing tetracosane(1).

Drug Information

Arthrobacter nicotianae KCC B35 isolated from blue-green mats densely covering oil sediments along the Arabian Gulf coast grew well on C10 to C40 n-alkanes as sole sources of carbon and energy. Growth on C20 to C40 alkanes was even better than on C10 to C18 alkanes. Biomass samples incubated for 6 hr with n-octacosane (C28) or n-nonacosane (C29) accumulated these compounds as the predominant constituent alkanes of the cell hydrocarbon fractions. The even chain hexadecane C16 and the odd chain pentadecane C15 were the second dominant constituent alkanes in C28 and C29 incubated cells, respectively. n-Hexadecane-incubated cells accumulated in their lipids higher proportions of C16-fatty acids than control cells not incubated with hydrocarbons. On the other hand, C28 and C29-incubated cells did not contain any fatty acids with the equivalent chain lengths, but the fatty acid patterns of the cell lipids suggest that there should have been mid-chain oxidation of these very long chain alkanes. This activity qualifies A. nicotianae KCC B35 to be used in cocktails for bioremediating environments polluted with heavy oil sediments.|Liver, heart, kidneys, muscle and adipose (perirenal and s.c.) /bovine/ tissues were collected from 6 animals for analysis of their hydrocarbon composition. Qualitative and quantitative determinations were carried out by gas chromatography and combined gas chromatography-mass spectrometry. Although differing in the proportions, a homologous series of n-alkanes ranging from n-C12-n-C31 was found in all samples. The isoprenoid hydrocarbons phytane and phytene (phyt-1-ene and phyt-2-ene) were also identified. (These findings have relevance to the health of humans consuming hydrocarbon-contaminated meats.) /n-Alkanes/

114.00 Days

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment. INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing. INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aliphatic hydrocarbons and related compounds/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... ./Aliphatic hydrocarbons and related compounds/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aliphatic hydrocarbons and related compounds/|Emergency and supportive measures. 1. General. Provide basic supportive care for all symptomatic patients. Maintain an open airway and assist ventilation if necessary. Administer supplemental oxygen. Monitor arterial blood gases or oximetry, chest radiographs, and ECG and admit symptomatic patients to an intensive care setting. Use epinephrine and other beta-adrenergic medications with caution in patients with significant hydrocarbon intoxication because arrhythmias may be induced. 2. Pulmonary aspiration. Patients who remain completely asymptomatic after 4-6 hours of observation may be discharged. In contrast, if the patient is coughing on arrival, aspiration probably has occurred. Administer supplemental oxygen and treat bronchospasm and hypoxia if they occur. Do not use steroids or prophylactic antibiotics. 3. Ingestion. In the vast majority of accidental childhood ingestions, less than 5-10 mL is actually swallowed and systemic toxicity is rare. Treatment is primarily supportive. Injection. For injections into the fingertip or hand, especially those involving a high-pressure paint gun, consult with a plastic or hand surgeon immediately, as prompt wide exposure, irrigation, and debridement are often required. /Hydrocarbons/|For more Antidote and Emergency Treatment (Complete) data for n-Tetracosane (7 total), please visit the HSDB record page.

tetracosane

Tetracosane Use and Manufacturing

Methods of Manufacturing

The liquefaction of coal provides the greatest variety of saturated hydrocarbons. The Fischer-Tropsch synthesis produces alkanes from syngas (CO + H2) in the range C1 to C30 or higher depending on the process variant: depending on the catalyst employed, the synthesis yields predominantly liquid hydrocarbons in the gasoline range, along with gases from C1 to C4 when iron-based catalysts are used, while cobalt-based catalysts produce longer chain hydrocarbons in the diesel and wax range that often undergo, depending of the desired product slate, further processing, especially for gasoline generation. While iron-based Fischer-Tropsch catalysts generate complex mixtures that also include branched and olefinic hydrocarbons, cobalt-based catalysts produce streams that are rich in n-alkanes and are therefore suitable raw materials for detergents and for wax products. /Saturated Hydrocarbons/|Suitable sources for n-alkanes with more than six carbon atoms are the appropriate petroleum distillate fractions, from which the n-paraffins can be isolated in high isomeric purity (= 95% linearity) by selective separation techniques, especially fractional distillation. /Higher n-Alkanes/

Uses

Gas chromatography analysis standard. Organic Synthesis.

Tetracosane: ACTIVE|Gas-phase dehydrogenation of n-alkanes over noble-metal catalysts yield the corresponding n-alkenes at low conversion rates (ca. 10%) with predominantly internal double bonds. The corresponding alkenes can be isolated in high purity by selective molecular-sieve processes. /Higher n-Alkanes/

Conradina canescens (Lamiaceae) is an endemic evergreen shrub native to Florida, Mississippi and Alabama, with no phytochemical or biological studies registered in the literature. Thus, a phytochemical study and a toxicity analysis of the chloroform extract obtained from the leaves of C. canescens were performed for the first time. In our preliminary screening, the crude extract and its fractions were subjected to cytotoxicity, antimicrobial and antileishmanial bioassays. The crude extract showed substantial cytotoxic, antimicrobial and antileishmanial activities. A total of six compounds, namely ursolic acid (62.4%), betulin (8.4%), beta-amyrin (4.6%), myrtenic acid (2.9%), n-tetracosane (1.4%), and oleanolic acid (1.1%), were isolated. The structures of the isolated compounds were established by spectroscopic studies using NMR and IR spectroscopy.|The external surface of all insects is covered by a species-specific complex mixture of highly stable, very long chain cuticular hydrocarbons (CHCs). Gas chromatography coupled to mass spectrometry was used to identify CHCs from four species of Sarcophagidae, Peckia (Peckia) chrysostoma, Peckia (Pattonella) intermutans, Sarcophaga (Liopygia) ruficornis and Sarcodexia lambens. The identified CHCs were mostly a mixture of n-alkanes, monomethylalkanes and dimethylalkanes with linear chain lengths varying from 23 to 33 carbons. Only two alkenes were found in all four species. S. lambens had a composition of CHCs with linear chain lengths varying from C23 to C33, while the other three species linear chain lengths from 24 to 31 carbons. n-Heptacosane, n-nonacosane and 3-methylnonacosane, n-triacontane and n-hentriacontane occurred in all four species. The results show that these hydrocarbon profiles may be used for the taxonomic differentiation of insect species and are a useful additional tool for taxonomic classification, especially when only parts of the insect specimen are available.|The chloroform-extractable lipid fraction of dissolved organic matter in seawater was analyzed by gravimetry, liquid chromatography, gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS). Gravimetric concentrations of dissolved lipids in the Gulf of Mexico were in the range of 60-160 mg/L in near-surface waters and 61-116 ug/L in near bottom waters and accounted for approximately 4% of the dissolved organic C. Over a 12-hr sampling period and a 5-day sampling period extensive variability in dissolved lipid quantity and quality were observed. The major percentage of extractable weight was collected in the polar liquid chromatographic fraction (55-95%). Gas chromatographic concentrations of the aliphatic fractions were in the range of 0.014-0.187 ug/L. Concentrations derived from gas chromatography were consistently lower than gravimetrically-derived concentrations. A number of compounds were tentatively identified by a combination of GC, GC-MS, and authentic standards. The major components of the analyzable dissolved lipids were n-alkanes (C16-C32), pristane, phytane, methyl, ethyl and propyl esters of fatty acids. Minor components included olefins and cycloalkanes, aromatics, short-chained acids, and possibly a lactone and an alcohol. All concentrations and compounds were indicative of a fairly pristine environment. The n-alkane distribution appears to be the result of marine and terrestrial inputs superimposed on a chronic low-level background of oil pollution. The fatty acid esters and other fragment molecules may be the result of the degradation of humic substances. A number of potential indicators of source were isolated. /n-Alkanes/|Petroleum-related contaminants in seafoods were analyzed. A GC (SIM) method was developed for the determination of contaminants, which covered 7 n-alkanes (C20-C32) and 7 polycyclic aromatic hydrocarbons (PAH), including benzo(a)pyrene, and dibenzothiophene (DBT). The detection limits were 2-3 ppb for n-alkane, 0.1-0.2 ppb for PAH and 0.2 ppb for DBT. The concentrations of petroleum-related contaminants in seafoods, collected either from waters that were outside the spill area or before the oil spill, were determined by the GC/MS (SIM) method. Levels of total n-alkanes ranged from nd (not detected) to 532 ppb and those of PAH and DBT ranged from nd to 15.5 ppb. The concentrations of n-alkanes and PAH in the visceral mass of squid and scallops were higher than those in their muscle tissues. /n-Alkanes/|Method: EPA-EAD 1625; Procedure: gas chromatography/mass spectrometry; Analyte: n-tetracosane; Matrix: water; Detection Limit: 1 ug/L.

Fatty Acyls [FA] -> Hydrocarbons [FA11]

Computed Properties

Molecular Weight:338.7
XLogP3:12.6
Rotatable Bond Count:21
Exact Mass:338.391251595
Monoisotopic Mass:338.391251595
Heavy Atom Count:24
Complexity:174
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes

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